Lawn mowers in which a cutter blade is rotatably mounted in a cutter housing and grass cuttings are discharged to outside the cutter housing from a scroll part of the cutter housing through a cut grass carrying passage are known. In a lawn mower of this kind, the scroll part and the cut grass carrying passage are formed integrally with the cutter housing.
A lawn mower in which a scroll part is formed integrally with a cutter housing like this and a bottom part of a cut grass carrying passage is formed separately is proposed in for example JP-UM-A-63-61223. This lawn mower will now be described on the basis of FIG. 11 and FIG. 12.
The lawn mower 220 shown in FIG. 11 has an engine 222 mounted on top of a cutter housing 221 and a cutter blade 224 attached to the output shaft 223 of this engine 222, and the cutter blade 224 is rotated inside the cutter housing 221 to cut grass.
As shown in FIG. 12, the cutter housing 221 has a scroll part 225 which allows rotation of the cutter blade 224 and in which grass cuttings cut by the cutter blade 224 swirl, and a cut grass carrying duct 226 through which the grass cuttings are carried from the scroll part 225 to outside the cutter housing 221.
The cut grass carrying duct 226 is made up of an approximately U-shaped cut grass passage part 227 formed integrally with the cutter housing 221, and a bottom plate 228 formed as a separate part covering the cut grass passage part 227.
However, in the lawn mower 220 of the related art described above, because only the bottom plate 228 has been made a separate component from the cutter housing 221, there has been the shortcoming that this is not enough to make the shape of the cutter housing 221 simple, and it is not possible to simplify the mold.
Also, in this lawn mower 220, because the cut grass passage part 227 and the scroll part 225 of the cut grass carrying duct 226 are formed integrally with the cutter housing 221 and the bottom plate 228 of the cut grass carrying duct 226 is formed as a separate piece, it is necessary for mounting parts 229 to be formed in three locations on the bottom plate 228. Consequently, there has been the problem that the number of fixing components such as screws increases and ease of assembly deteriorates.
Accordingly, a lawn mower has been awaited with which it is possible to form the cutter housing easily by split construction and it is possible to achieve improved ease of assembly of the pieces of the split construction and to achieve improved productivity.